Chapter20 Mental Events DonaldDavidson Mental events such as perceivings, rememberings, decisions, and actions resist capture 1 in the nomological net of physical theory. How can this fad be reconciledwith the causalrole of mental events in the physical world? Reconciling heedom with causal determinism is a special case of the problem if we suppose that causaldeterminism entails capture in, and heedom requires escapeHorn , the nomological net. But the broader issue can remain alive even for someonewho believes a corred analysis of &ee action revealsno conflid with determinism. Autonomy( &eedom, self-rule) mayor may not clashwith determinism; anomaly( failure to fall under a law) is, it would seem, another matter. I start Horn the assumptionthat both the causaldependence , and the anomalousness, of mental events are undeniable fads. My aim is therefore to explain, in the face of apparentdifficulties , how this can be. I am in sympathy with Kant when he says, it is as impossiblefor the subtlest philosophy as for the commonestreasoning to argueheedom away. Philosophy must thereforeassume that no true contradiction will be found between heedom and natural necessityin the samehuman actions, for it cannot give up the idea of nature any more than that of heedom. Henceeven if we should never be able to conceive how &eedom is possible, at least this apparent contradiction must be convincingly eradicated. For if the thought of heedom contradids itself or nature . it would have to be surrenderedin competition 2 with natural necessity. Generalizehuman actions to mental events, substitute anomaly for &eedom, and this is a description of my problem. And of course the connection is closer, since Kant believed &eedom entails . anomaly " " Now let me try to formulate a little more carefully the apparent contradiction about mental events that I want to discussand finally dissipate. It may be seen as stemmingHorn three principles. The first principle assertsthat at least some mental events interad causally with physical events. ( Wecould call this the Principle of CausalInteraction .) Thus for example if someone sank the Bismarck, then various mental events such as perceivings, notings, calculations, judgments, decisions, intentional actions and changesof belief played a causalrole in the sinking of the Bismarck. In particular, I would urge that the fad that someone sank the Bismarckentails that he moved his body in a way that was causedby mental events of certain sorts, and that this bodily movement in turn 3 causedthe Bismarckto sink. Perception illustrates how causality may run Horn the physical to the mental: if a man perceives that a ship is approaching, then a ship approaching must have causedhim to come to believe that a ship is approaching. ( Nothing dependson acceptingthese as examples of causalinteraction .) Though perception and action provide the most obvious caseswhere mental and physical events interad causally, I think reasonscould be given for the view that all 138 Donald Davidson mental events ultimately, perhaps through causalrelations with other mental events, have causalintercourse with physical events. But if there are mental events that have no physicalevents as causesor effects, the argumentwill not touch them. The second principle is that where there is causality, there must be a law: events related as cause and effect fall under strict deterministic laws. ( We may term this the Principle of the Nomological Character of Causality.) This principle, like the first, will be treated here as an , I shall of 4- assumption though say something by way interpret aHon . The third principle is that there are no strict deterministiclaws on the basisof which mental eventscan be predictedand explained( the Anomalism of the Mental). The paradox I wish to discussarises for someonewho is inclined to accept these three assumptionsor principles, and who thinks they are inconsistentwith one another. The inconsistencyis not, of course, formal unlessmore premisesare added. Nevertheless it is natural to reasonthat the first two principles, that of causalinteraction , and that of the nomological characterof causality, together imply that at least some mental events can be predicted and explained on the basis of laws, while the principle of the anomalismof the mental deniesthis . Many philosophershave accepted, with or without argument, the view that the three principles do lead to a contradiction. It seemsto me, however, that all three principles are true, so that what must be done is to explain away the appearanceof contradiction; essentiallythe Kantian line. The rest of this paper falls into three parts. The first part describesa version of the identity theory of the mental and the physical that shows how the three principles may be reconciled. The secondpart arguesthat there cannot be strict psychophysicallaws ; this is not quite the principle of the anomalismof the mental, but on reasonableassumptions entails it. The last part tries to show that from the fact that there can be no strict psychophysicallaws , and our other two principles, we can infer the truth of a version of the identity theory, that is, a theory that identifies at least some mental events with " ' physical events. It is clear that this proof of the identity theory will be at best conditional, since two of its premisesare unsupported, and the argument for the third may be found less than conclusive. But even someoneunpersuaded of the truth of the premisesmay be interestedto learn how they may be reconciledand that they serve to establisha version of the of the mental. ' identity theory Finally, if the argument is a good one, it should lay to rest the view, common to many friends and some foes of identity theories, that support for such theories can come only from the discovery of psychophysicallaws . I The three principleswill be shown consistentwith one another by desaibing a view of the mental and the physical that contains no inner contradiction and that entails the three principles. According to this view, mental events are identical with physical events. Events are taken to be unrepeatable, dated individuals such as the particular eruption of a volcano, the (6rst) birth or death of a , the of the 1968 person" playing World Series, or the historic utterance of the words You fire " , may when ready, Gridley. We can easily &ame identity statementsabout individual eventsi examples (true or false) might be: The death of Scott = the death of the author of Waverleyi The assassinationof the Archduke Ferdinand= the event that started the First World Wari = The eruption of Vesuviusin AiD. 79 the causeof the destructionof Pompeii. Mental Events 139 The theory under discussionis silent about process es, states, and attributes if these differ Horn individual events. What does it mean to say that an event is mental or physical? One natural answeris that an event is physical if it is describablein a purely physical vocabulary, mental if describablein mental terms. But if this is taken to suggestthat an event is physical, say, if some is true of it, then there is the . Assumethat physical' predicate ' following difficulty the x took at Noosa Heads to the ; then so predicate place' belongs physical' vocabulary also must the x did not take at Noosa Heads to the predicate ' place belong ' physical vocabulary. But the predicate x did or did not take place at Noosa Heads is true of ' every event, whether mental or physical. We might rule out predicatesthat are tauto- true of every event, but this will not sinceevery event is truly describable logically ' ' help' ' either by x took placeat Noosa Heads or by x did not take place at Noosa Heads. A 6 different approachis needed. We may call those verbs mental that expresspropositional attitudes like believing, intending, desiring, hoping, knowing, perceiving, noticing, remembering, and so on. Such verbs are characterizedby the fact that they sometimes feature in sentences with subjectsthat refer to persons, and are completedby embeddedsentences in which the usualrules of substitution appearto break down. This criterion is not precise, sinceI do not want to include these verbs when occur in contexts that are extensional ' they ' fully (' He knows Paris, ' He perceives the moon may be cases), nor exclude them whenever they are not followed by embeddedsentences . An alternative characteriza- tion of the desiredclass of mental verbs might be that they are psychologicalverbs as usedwhen create nonextensionalcontexts . they apparently ' ' Let us call a of the form the event that is M or an sentenceof the ' description open form event x is M' a mental or a mental sentenceif and if the ' ' description open only expressionthat replacesM containsat leastone mental verb essentially. (Essentially, so as to rule out caseswhere the description or open sentenceis logically equivalent to one not containing mental vocabulary.) Now we may say that an event is mental if and only if it has a mental description, or (the description operator not being primitive) if there is a mental open sentencetrue of that event alone. Physical events are those picked out by descriptionsor open sentencesthat contain only the physical vocabulary essentially. It is lessimportant to characterizea physical vocabulary becauserelative to the mental it is, so to speak, recessivein determining whether a description is mental or physical. (Therewill be some commentspresently on the nature of a physical vocabulary , but thesecomments will fall far short of providing a criterion.) On